Rochester B bowl gasket mystery
 

I rebuilt my carb, an early to mid '60s Rochester B without an ID tag. It went smoothly, however, I came across one puzzling thing. The bowl gasket I pulled out didn't match what I received in the Quadrajet kit. I went to their website and the one that matches is for a '49 - '51 Rochester B (the left one).

The whole thing has me asking questions, like, is this just one of the many Rochester variants; did someone perform a rebuild with the incorrect bowl gasket; what if I just use the one that came with the rebuild kit; has any forum members been in the same situation?

I ordered the matching gasket, but I'm curious as to what would happen if I installed the newer one. I'm open to opinions, speculation, and past experiences.

Re: Rochester B bowl gasket mystery
 

Anyone?

Re: Rochester B bowl gasket mystery
 

What are the numbers on the very bottom of the throttle body assembly. Should be a number cast into the face off it. That will help narrow down the year. Also...does it have a fast idle adjusment on the top of the barb? There were alot of different variations of the model B

Re: Rochester B bowl gasket mystery
 

Other than a manual choke, your exploded diagram is exactly what mine looks like, I've included some photos. The base of the throttle body is stamped 7004522.

BTW, it just struck me that I have more photos of my truck's various parts on my smart phone than the kids ... is this acceptable or do I need an intervention?

Re: Rochester B bowl gasket mystery
 

Rochester show it as a 67-72 6 cyl carb, which would be the 250 or 292. I have the same carb on my 63 230. My carb came from Holley remanufactured. The gasket that came with the rebuild kit (the one on the right), is the gasket that is in my carb. Now...keep in mind that the throttle bases are interchangeable on alot of the carbs. I would also suggest finding the #'s on the carb itself and I can run those for you. Odds are you have a 67-72 6cyl carb and was rebuilt with an earlier 1bbl carb kit. You should be able to place the gasket on the bowl and see if the holes line up though.

Re: Rochester B bowl gasket mystery
 

I noticed the active thread about the rochester model B carb going on, and wanted to offer some possible usefull info. I have a early OEM factory service and operation manual from Rochester Products. They are scanned in PDF format and are really a valueable piece of info to have. I would love to pin it to the board somehow, but I can email them to someone if interested. Thanks

Re: Rochester B bowl gasket mystery
 

Check with the moderator...maybe able to put in the FAQ section

Re: Rochester B bowl gasket mystery
 

I was looking for casting numbers on the air horn and bowl. Saw some 2 digit numbers, but will double check. I know a PO played with it at one point because it had 4 different size bolts holding the air horn to the bowl. During the rebuild, I tapped them all to the same size and thread.

UltraHD4me - is it similar to this ... http://chevy.oldcarmanualproject.com.../5020mts00.htm ... because that would be a great post

Re: Rochester B bowl gasket mystery
 

ACK: They may be the same, the manual the link takes you too is a GM factory manual. The one I have is a factory "Rochester Products" manual.

Re: Rochester B bowl gasket mystery
 

Here is the front cover of the manual I have.

Re: Rochester B bowl gasket mystery
 

I have 2, maybe 3 parts carbs if you find that you may have some wrong pieces or issues after rebuild. Well get you going one way or the other.

Re: Rochester B bowl gasket mystery
 

Found the casting #s:

Air horn: 7025523
Throttle body: 7025382

I couldn't find anything useful on the Internet.

Re: Rochester B bowl gasket mystery
 

The carb is rebuilt and back on, but it isn't getting gas. It's a mechanical pump, so I'm assuming the carb needs to be primed. Would it make sense to disconnect the fuel line at the carb and turn over the engine a few times to see if I can get things flowing or bite the bullet and fill the bowl with gas by removing the air horn? Any other suggestions?

Re: Rochester B bowl gasket mystery
 

Being patient isn't my strong suite. I trickled some gas into the carb, started it up, let it die, did it again and the 2nd time she jumped to life! I'll take her out for a test when it's daylight, but so far it's looking like the rebuild has been a success! Thanks guys for the help.

Re: Rochester B bowl gasket mystery
 

ACK- the replacement gasket on the right is the one that fits my "B" on my 63 292.

I dont have a tag and couldnt determine any castings numbers on it. Even though mine is a B the choke butterfly has BC stamped in it. I dont have any experience with these but it seems that a lot if parts are very interchangable.

After rebuilding mine, I have reset the floats twice. First time they were too high and gas was pouring out the biwl gasket. Second time it wont idle unless I constantly adjust the choke with my hand. Its acting like the float is too low, but it is at 1 11/32". I know its supposed to be at 1 9/32 but I didnt think it should chug so much when the throttle is at idle.
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Re: Rochester B bowl gasket mystery
 

Thanks for all the info, guys.